JPS58191061A - Bus connecting device - Google Patents

Abstract

PURPOSE:To realize a dual computer system without using any special connecting means between both systems, by using a means which detects an interruption of processing of own system connected to a common bus, then makes contact with the other system. CONSTITUTION:A connection command is fed to the 1st bus connecting device 71 when the 1st processor 41 connected to the 1st bus 1 uses an input/output device 53 connected to a common bus 3. The device 71 receives the connection command and performs a connecting action to informs the result of connection to the processor 41. In case the bus 3 is not connected by the 2nd bus connecting device 72, the device 71 is connected by the processor 41. Thereafter, the processor 41 can use the device 53 connected to the bus 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Description of the Technical Field) The present invention relates to a bus coupling device for a data processing bag, particularly to a bus coupling device used in a dual computer system.

(Description of Prior Art) Generally, in a data processing system to obtain high reliability, it is recommended to adopt a dual system or more computer system using at least two or more processing devices, as shown in Figure 1. many. That is, the dual system computer system shown in FIG. 6
2, first and second bus coupling devices 71 and 72, and a communication device 8 between processing device systems. In such a dual-system computer system, the input/output M locations are often shared, mainly from a cost standpoint. In order to share the input/output device, for example, the first straddle second processing device 41
, 42 are connected to the system connected to the shared third and fourth input/output devices 53 and 54, and each system is connected to $1 and the second bus coupling device 71. , 72.

Conventionally, in such a dual-system system, an si and a second bus coupling device 71 are used to configure a common bus.
, 72, there is a drawback that an inter-processing device system communication device 8 is required for synchronizing the processing devices 41, 42. In other words, when a system connected to a common bus in a dual-system computer system as shown in Figure 1 interrupts processing for some reason, the KFI releases the connection between this system and the common bus, and also disconnects the system from the common bus. Notifies the system processing device of the interruption of processing. On the other hand, the other system's processing device that has received the communication connects the common bus to its own system's bus and takes over the processing. Synchronization is the act of having the other processing device resume processing when one processing device interrupts processing, and synchronization is essential in dual-system computer systems. In a processing device, processing may be interrupted normally, but it is often the case that some kind of abnormality occurs in Kfl at the time of interruption, making it impossible to continue the processing.

Therefore, it is necessary to constantly monitor the status of the system and, in the event of an abnormality, to notify and contact other systems of the abnormality. This function may be realized by the communication device 8 between the two systems, but it may also be realized by providing a separate system monitoring device.

As explained above, in a dual system computer system, the buses can be connected appropriately. 2 bus coupling device 71.
In addition to 72, communication means for handing over processing to another system and means for monitoring system abnormalities are required. but,
Conventional dual-system computers did not realize these devices and means at the same time.

(Detailed Description of the Invention) An object of the present invention is to use a bus coupling device that is equipped with means for detecting when the processing of its own system connected to a common bus is interrupted and communicating with other systems. Therefore, it is an object of the present invention to provide a bus coupling device for eliminating the above-mentioned drawbacks and realizing a dual-system computing system without separately preparing communication means between the two systems. Another object of the present invention is to provide a bus coupling device that can realize a duplex system that is advantageous not only in terms of operability but also in terms of cost by easily realizing this communication means.

(Description of structure and operation of the invention) A pair of bus coupling devices according to the present invention are used in a dual-system computer, and the first and second bus coupling devices are used for the first and second processing device systems, respectively. $2 bus and a common bus shared by the first and second processing units.

Each bus coupling device can set both buses in a coupled state or in a released state, and is composed of first and second bus coupling circuits, a connection control circuit, and an activation control circuit. The first and second bus coupling circuits are cascaded together and provide logical control of the interface between the first or second bus and the common bus. The connection control circuit monitors the state of the second bus coupling device in the processing device system @1, monitors the state of the bus coupling device Fi$1 in the second processing device system, and connects each other system. This is to set the self-system to the connected state when it is not in the connected state. The activation control circuit detects a change in the bus connection state of the other system and performs control so that data transfer can be activated in the own system. The pair of bus coupling devices are configured to maintain a close relationship between the first and second processing system.

(Description of Examples) Next, the present invention will be described in detail with reference to the drawings. FIG. 2 is a partial diagram showing a portion of an embodiment of a dual system computer system using a bus coupling device. The bus coupling bag [ri] of this embodiment is prepared for each processing device system, and combines a pair of bus coupling devices into one common bus 3 on the common bus side. FIG. 2 shows that the first bus 1 and the common bus 3 are coupled to a first bus coupling device 71 connected to the first bus IK. It is also prepared to monitor the status of the bus coupling device 72 of the 9Fi other system shown in FIG. 2, and shows an interface bus between the bus coupling devices 71 and 72.

In FIG. 2, when the first processing device 41 connected to the first bus 1 uses the input/output device 53 connected to the common path 3, it is connected to the first bus coupling device 71. To send out commands. The first coupling device 71 that has received the connection command performs a connection operation and notifies the first processing device 41 of the result. When the common bus 3 is not in the coupled state by the second bus coupling device 72, the bus coupling device 71 of '@1 is connected to the input/output device 53 connected to the coupling bus 3 by the first processing device 41. can be used. Also, the second bus coupling device 72 connected to the second bus 2 is connected to the first bus coupling device 71 via the interface bus 9t between the bus coupling ill 71 and 72.
know that is in a connected state. Here, in order to use the input/output device 53 connected to the common bus 3, the processing device 42 connected to the second bus 2 sends a connection command to the second bus connection bag R72K. Even so, the first bus coupling device 71 is already in the coupling state. For this reason, the second path coupling device 72 cannot enter the σ coupling state. When the use of the input/output device 53 connected to the common bus 3 is interrupted for some reason, the first processing device 41tI'! A release command is sent to the first bus coupling device 71, and at the same time, the processing device communication device 8 is used to notify the second processing device [42] of the suspension of processing. If the second processing device 142 that received this notification needs to use the input/output device 53 connected to the common path 3, the second processing device 142
A connection command is sent to the bus coupling device 72 of. Connection command received! The bus coupling device 72 of J2 performs the connection operation and notifies the second processing device @42K of the result. FIG. 3 is a flowchart showing the procedure of this process.

FIG. 4 shows first and second bus coupling devices 7 according to the present invention.
1 and 72 are flowcharts showing the processing procedure when using 1 and 72. In FIG. 4, the first bus coupling device 71 is in a coupled state using the same procedure as in the conventional process. The first process ii 41 interrupts the process and the first bus coupling device 7
1 is released from the coupled state, the second bus coupling device 72t! The first bus coupling device 71 detects a change in state from the coupled state to the released state, and the second processing device 4
Start data transfer for 2. If it is necessary to use the 183 input/output device 53 connected to the common bus 3, the I82 processing unit that received the data transfer command from the second bus coupling device 72 [42H]
A connection command is sent to the common bus 3 to put the common bus 3 into a connected state.

Next, the configuration of the first or second bus coupling bag [71, 72] will be explained in detail using Figure 5.

In the first bus coupling device 71, the bus coupling circuit section 12
1 is a first bus coupling path 1211 for controlling the interface with the first bus 1 of the first processing unit system, and a first bus coupling path 1211 for controlling the interface with the common path 3. and a second bus coupling circuit 1212. A connection command and a release command from the first processing device 41 are transmitted from the first bus coupling circuit 1211 to the first connection control circuit 101. Also, the first result of the connection operation is
The notification to the processing device 41 is also sent to the first bus coupling circuit 12.
11 will do it. The second bus coupling circuit 1212 that controls coupling with the common path 3 has meaning only in the U coupling state.

There is no essential difference between the conventional bus coupling device and the $1 or second bus coupling device 71, 72 according to the present invention.

The connection-side circuits 101 put the bus coupling device 71 of Alternative Plan 1 into a coupled state and a released state in response to a connection command and a release command from the first processing device 41. In addition, the connection control circuit 10
1 is connected to the bus coupling device 72 of another system by an interface bus 9 between the bus coupling devices 71 and 72, and has a function of notifying the state of the own processing device 41 to the other processing device 42, as well as the status of the other processing device 42. Contains a function to know. Start-up control circuit 111 #-1$2 processing device 4
2, the first bus coupling circuit 121
Start 1.

Next, an example of the configuration of the connection control circuit 101 and the activation control circuit 111 of the first and Fi second bus coupling devices 71 and 72 according to the present invention is shown in FIG.

Path coupling circuit 1211 Fi Outputs the connection control circuit 101 and activation control circuit 111KCNCT+ signal in response to a connection command from the first processing device 41.

When the CNCT+ signal is sent, the connection control circuit 101
Then, the first D-type flip-flop 511, which controls the coupled state and the released state, is set to the coupled state. However, when the bus coupling device 72 of another system is already in the coupled state, a BUOY- signal indicating the coupled state is sent via the driver/receiver circuit 561, and this signal K
Therefore, the first D-type flip-flop 511 cannot be set. In the startup control circuit 111, the timing generation circuit 531 is set, and after the time required for the connection operation has elapsed, the TRIG+
A signal is output, which causes the first path coupling circuit 12
11 is activated. In addition, the first path coupling circuit 1211
An RL8- signal is sent to the connection control circuit 101 in response to a release command from the processing device 41 of fl$1. As a result, in the connection control circuit 101, the first D-type flip-flop 5
11 is reset and becomes a released state.

The above operation is also performed in the conventional bus coupling device, and there is essentially no difference from the bus coupling devices 71 and 72 according to the present invention.

Now, let us consider a case where the bus coupling device 72 of another system changes from the coupled state to the released state. By modifying the BU8Y- signal sent via the driver/receiver circuit 561,
$2 D for state change detection in startup control circuit 111
A shaped frig-flop 521 is set. The signal sent out from the second D-type flip-flop 521 is sent out via the OR gate circuit 551 and activates the first path combination circuit 1211. Second D-shaped flip 70 knob 52
In this embodiment, the timing for resetting 1 is when a connection command is received. This makes it possible to notify the processing device 41 of the WLL of the own system about the interruption of the processing of the other system. Furthermore, as is clear from the example in Figure 6,
Regardless of whether the cause of the bus coupling device 72 of the other system being released is due to a cancellation command from the second processing device 42 or due to an abnormal condition, the bus coupling device 71.72t! of the present invention! can work the same way. That is, no matter how the system monitoring method is implemented, the bus coupling device according to the present invention can be used without any inconvenience.

(Detailed Description of the Invention) As described above, the present invention provides an interface bus for detecting a change in the state of a bus coupling device of another system and notifying a processing device of the own system of the state change. To connect between devices! In a dual-system computer system, there is an effect that the processing device can be aware of state changes without the need for any other means of communication.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of a dual system computer system according to a known technique, FIG. 2 is a block diagram showing an example of the connection of a pair of bus coupling devices according to the present invention, and FIGS. Figure 4 is a flowchart of an example of processing performed using a bus coupling device, Figure 5 is a block diagram showing the configuration of an embodiment of a pair of bus coupling strings according to the present invention, and Figure @6 is a flowchart of an example of processing performed using a bus coupling device. FIG. 2 is a block diagram showing a configuration example of a connection control circuit and a startup control circuit in the device. 1.2.3...Bus 41, 42...Processing device 5
1 to 54...I/O devices 61, 62...1 storage device 71, 72...Bus coupling device 8...Processing device communication device 9...Interface path 101, 102...Connection Control circuits 111, 112...Start control circuits 121, 122...Bus coupling circuit units 1211, 1
212, 1221, 1222...path coupling circuit 5
11, 521...D type flip-flop 531...
・Timing generation circuit 541...Gate circuit 551...OR gate circuit 561...Driver/receiver Patent applicant NEC Corporation Agent Patent attorney Inoro Maki

Claims (1)

[Claims] a first processor system connected to the first and second processing device systems, respectively;
and a second bus, and a common bus shared by the first and second processing device systems, the first and second paths and the common bus being shared by the first and second processing device systems, respectively. In each of the eleventh and second bus coupling devices that are connected to the bus and can set the two buses to a coupled state or a released state, the first and second bus coupling devices are connected to the first and second processing device systems. To logically control the interface between the second path and the first common bus,
$1 and a second bus coupling circuit connected in cascade, respectively, and the first processing device system monitors the state of the second bus coupling device, and the second processing device system monitors the state of the second bus coupling circuit. A connection control circuit for intelligently observing the state of the bus coupling device No. 1 and setting its own system to a coupled state when the other system is not coupled, and detecting a change in the state of the path coupling state of the other system. , the first and second path connections from the activation control circuit for controlling the activation of data transfer in the own system! ! 11 are satisfied, and the first
and a second processing device system.